NEW AND EFFICIENT APPROACH TO THE SYNTHESIS OF PENTACOORDINATE SPIROBICYCLIC PHOSPHORANES

Pentacoordinate spirobicyclic 2-phenoxy-1,3-phenylenedioxo-1,3,2-imino (alkyl)- acetoxyphosphoranes are synthesized through a new and efficie nt method whereby phosphorus pentachloride is displaced stepwise by ca techol, an N,O-bis(trimethylsilyl)amino acid and phenol (pathway A) or catechol, phenol and an N,O-bis(trimethylsilyl)amino acid (pathway B) ; this method has advantages of high yields, rapid reaction times and easy operation, which might provide a new route for the synthesis of o ther pentacoordinate phosphoranes.